In vertebrates, the collection of flat and irregularly shaped bones (or cartilage) that enclose the brain and the organs of sight, hearing, and smell, and provide support for the jaws. In mammals, the skull consists of 22 bones joined by sutures. The floor of the skull is pierced by a large hole (foramen magnum) for the spinal cord and a number of smaller apertures through which other nerves and blood vessels pass.
The skull comprises the cranium (brain case) and the bones of the face, which include the upper jaw, enclosing the sinuses, and form the framework for the nose, eyes, and roof of the mouth cavity. The lower jaw is hinged to the middle of the skull at its lower edge. The opening to the middle ear is located near the jaw hinge. The plate at the back of the head is jointed at its lower edge with the upper section of the spine. Inside, the skull has various shallow cavities into which fit different parts of the brain.
The human skull has evolved from robust to gracile in the past 5. 5 million years; it exhibits neoteny (infantilism), whereby the youthful features of ancient human species are retained in the adult skulls of modern humans— probably to make room for the evolving and enlarging brain.
The bony skeleton of the head of vertebrates.
1. To hit on the head
2. To unintentionally hit (a golf ball or shot) with the bottom edge of the clubface